<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport"
        content="width=device-width, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0, user-scalable=no">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <style>
        .box {
            margin-left: 50px;
            background: red;
        }

        .box::after {
            content: "";
            display: block;
        }


        .box1 {
            float: left;
            width: 200px;
            height: 200px;
            background-color: blue;
        }

        .box2 {
            width: 400px;
            height: 100px;
            background: cyan;
          
        }
        /*
      *{
        margin: 0;
        padding: 0;
      }

      p {
        color: #f55;
        background:yellow;
        width: 200px;
        line-height: 100px;
        text-align: center;
        margin:30px;
      }
      div{
        overflow: hidden;
      }*/

     /* body{
        width: 100%;
        position: relative;
      }
      .left{
        width: 100px;
        height: 150px;
        float: left;
        background: rgba(139,214,78);
        text-align: center;
        line-height: 150px;
        font-size: 20px;
      }
      .right{
        overflow: hidden;
        height: 300px;
        background: rgba(170,54,236);
        text-align: center;
        line-height: 300px;
        font-size: 40px;
      }*/
    </style>
</head>

<body>
    <div class="box">
        <div class="box1"></div>
        <div class="box2"></div>
        <!-- <div style="clear: both;"></div> -->
    </div>
    <script>

    </script>
</body>

</html>